The present invention relates to an autochanger for storing items of recording media and transferring these to and from a read/write mechanism. The specific embodiment which will be described relates to an autochanger for digital audio tapes. In this field various terms are used for tape autochangers including xe2x80x9cstackersxe2x80x9d, xe2x80x9clibrariesxe2x80x9d, xe2x80x9cautoloadersxe2x80x9d, xe2x80x9cloadersxe2x80x9d, xe2x80x9cautochangersxe2x80x9d and xe2x80x9cchangersxe2x80x9d.
There are very many examples of known autochangers for tape cassettes of various kinds and also for other forms of media, such as disk. One example is described in European Patent No. 0 197 099 and discloses a tape autochanger in which tape cassettes are stacked in a fixed magazine and are transferred to and from a fixed tape drive mechanism by a cassette displacement mechanism which moves vertically along the stacked cassettes and horizontally between the magazine and the tape drive mechanism.
In an autochanger for tape cassettes disclosed in European patent application No. 0 398 199 (Mitsubishi), cassettes are mounted on a rotatable base which pivots to bring a selected cassette into engagement with a drive mechanism. In other embodiments described in that patent application, the drive mechanism is movable into contact with a selected cassette.
Another example is the autochanger described in European patent application No. 0 392 620 (Laser Magnetic Storage) having a magazine storing tape cassettes in a single vertical stack and a vertically movable elevator for transporting cassettes from the back of the magazine to a drive mechanism.
A further example is the tape autochanger described in European patent application No. 0 467 187 (Pierrat). The autochanger described stores cassettes on two decks with mechanical linkages for shunting the cassettes linearly along the decks from and to a pick up position where they can be picked up by a gripper which moves vertically and horizontally to transfer the cassettes between the storage area and a tape drive. A similar design of tape autochanger is described in U.S. Pat. No. 5,089,920 (WangDAT).
According to the present invention we provide apparatus for storing items of recording media and for transferring media items to and from a mechanism for reading and/or writing to the media items, said apparatus comprising:
a storage area for storing a plurality of media items so that these are spaced both around and along an axis, said mechanism being in a location which is fixed relative to said storage area;
means for rotating the stored media items as one body about said axis so as to permit access to any of the media items from one direction;
transfer means operable to collect media items from said one direction and to transfer media items between the storage area and said mechanism.
The present invention provides an autochanger which is able to be particularly compact whilst permitting easy access to the stored media items without the need for complicated mechanical assemblies for moving the media items within the autochanger.
The present invention also has the significant advantage of allowing access to any of the media items from one direction.
In the particular embodiment to be described the axis of rotation is parallel to the direction of movement of the transfer means between the storage area and the mechanism.
Preferably, the apparatus together with said mechanism is configured to fit within a standard peripheral form factor housing. This feature provides an autochanger having the considerable advantage of fitting within a standard peripheral form factor. Thus it can easily be built into a standard computer peripheral housing in a manner which is safe in that no parts protrude or are exposed and which is also aesthetically pleasing. By standard peripheral form factor is meant the peripheral form factors which are de-facto standards or official standards and are widely recognised as such. Examples of standard peripheral form factors are 8xe2x80x3, 5 xc2xcxe2x80x3 and 3 xc2xdxe2x80x3 form factors. In the embodiment to be described, the autochanger holds digital audio tape (DAT) cartridges (also called cassettes) and fits within a standard 5 xc2xc inch peripheral form factor.
Preferably, the apparatus is adapted to receive a magazine carrying media items and the rotating means is operable to rotate the magazine. This allows several tape cartridges to be loaded or unloaded from the autochanger at one time. In the embodiment to be described there is a toothed drive wheel for engaging teeth on the magazine to help retract and eject the magazine.
Media items, such as DAT cartridges, may be stored in two stacks equally spaced around said axis of rotation. The stored media items need to be rotated through 180xc2x0 to achieve access to all of them from one direction. Alternatively, the media items may be stored in staggered formation spaced around said axis of rotation e.g. so that rotations of 90xc2x0 are required to achieve access to all of the media items from one direction. In the embodiments to be described, the autochanger can store up to six DAT cartridges.
The means for rotating the media items may be a turntable, which may be mounted on the underside of the top plate of a housing for the apparatus so as to be rotatable to and fro through 180xc2x0.
The transfer means may comprise a platform configured to transport a media item between the storage area and the mechanism and a picker device which is movable relative to the platform to move media items onto and off the platform. The picker device may comprise opposed fingers for engaging respective sides of a media item, for example by engaging notches in its side edges. In embodiments to be described, the picker fingers are biassed inwardly and the apparatus comprises means for automatically deflecting the picker fingers outwardly. In those embodiments the picker fingers are pivotably mounted and the deflecting means comprises two rods movable in the same direction by a deflecting member so that each rod abuts one of the picker fingers and deflects it outwardly. In this way, only one deflecting member is required to open the two picker fingers.
In one embodiment, for use with media items having spaced sides and a rib extending between said sides, the picker device comprises picker fingers mounted for movement with a component of motion towards one another, each picker finger having two opposed faces oriented relative to one another to define a tapered opening, whereby upon movement of the picker fingers towards a media item located therebetween said tapered openings accommodate respective sides of the media item and a portion of each picker finger engages said rib for movement of the media item onto and off the platform.
Apparatus of the present invention may comprise means for moving the transfer means between the storage area and the mechanism in the form of a slidable plate having a cam which co-operates with the transfer means and is profiled so that horizontal sliding of the plate causes vertical movement of the transfer means. Preferably, the cam is stepped in shape so as to define plurality of vertical positions for the transfer means. The cam may be in the form of a groove engaged by a connecting pin on the transfer means. For added stability the apparatus preferably also comprises vertical guide means positioned adjacent the cam for guiding the vertical movement of the transfer means. The vertical guide means may be a fixed plate having a vertical groove providing the vertical guide means.
In the embodiment to be described the first slidable plate is positioned on one side of the apparatus and a second slidable plate positioned on the opposite side of the apparatus and interconnected to the first slidable plate so that sliding movement of one of the slidable plates causes the other slidable plate to slide in the opposite direction. The first and second slidable plates may be interconnected by a pivotably mounted arm. The second slidable plate may comprise a cam oppositely profiled to the cam of the first slidable plate and which also co-operates with the transfer means. This provides a stable arrangement for lifting and lowering the platform supported on both sides.
There is a door in the apparatus for enabling media items to be inserted and ejected. In the embodiment to be described movement of one or more of the slidable plates effects opening of a door in the apparatus for receiving media items. In that embodiment, movement of one or more of the slidable plates also effects locking of the door for receiving media items. This arrangement has the advantage of reducing the number of components used in the apparatus.
According to a second aspect of the present invention we provide autochanger apparatus comprising:
a generally elongate housing;
a mechanism for reading and/or writing data items which is positioned at the base and rear of the housing and having an opening facing forwardly in the housing for receiving media items;
an area for storing media items above the mechanism;
transfer means positioned at the front of the housing for transporting media items between the storage area and the mechanism, and
means for rotating stored media items as one body so that all stored media items are accessible to the transfer means.
In the description and in the claims, the terms vertical, horizontal, and the like are used for descriptive purposes. However, it is understood that the embodiment of the invention described here is capable of operation in any orientation and the terms so used are only for the purpose of describing relative positions and are interchangeable under appropriate circumstances. For example, the tape cartridges are described as being held as two vertical stacks in the magazine. The autochanger may be used on its side in which case the terms vertical and horizontal need to be interchanged.